Effects of dead time and semiconductor device voltage drops of output voltage of multilevel converters

This paper presents the results of a study of the effect of dead time and finite semiconductor device voltage drops on the output voltage of three-level neutral point clamped power converters. Results showed that finite voltage drops and dead time caused a DC voltage shift, and lowered the base harmonic amplitude of output voltage. These effects were analysed and the results confirmed via simulation models. Voltage drops effect was confirmed using Ansys Simplorer, while the dead time effect was confirmed using Matlab. The results showed that the output voltage of the three-level neutral point clamped converters was dependant on the listed parameters. A method is proposed to suppress the negative effects these parameters have on converter voltage.